The sources who spoke with the AP requested anonymity because they were not authorized to speak for Thompson. Politico reports that the former Wisconsin governor has informed friends of plans to run for Senate in 2012.

Thompson has teased voters before. He toyed with running for the Senate in 2010, and entered and exited the 2008 presidential race. But top Republicans say he is putting out feelers about a run because it is an open seat and he sees the electorate as favorable.

Thompson was President George W. Bush's first secretary of the Department of Health and Human Services.